<!DOCTYPE html>
<html>
<head lang="en">
    <meta charset="UTF-8">
    <title>比较运算符</title>
</head>
<body>
<script >
    var x = 3;
    var y = 3;
    var z = "3";
    alert(x == y);
    alert(x === y);
    alert(x === z);
</script>

</body>
</html>